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Discussion Starter #1
I was gifted a 2003 civic si k20a3 and it was sitting for around five years and all it needed was a new alternator and it started right up! But after about two day after that I started it and it consistently started surging from 1k-2k rpms and it threw an idle air control system code so I replaced it and nothing so then I replaced the map and that did a little bit after that once I started it it would do the hunting then once warm it settles at 2k rpms and will not go on so I tryed putting it on a hill and bleeding the coolant system of air. STILL NOTHING! So today I checked the PCV valve and it’s perfect I don’t know what it could be and I forgot to mention that it drives fine. Any ideas?
 

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I had success cleaning the iacv until the drum can roll smoothly. I'd check for any other potential vacuum leaks, brake booster system can leak, evap system can leak, any vacuum switching valves can leak, gaskets can leak.
 

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Discussion Starter #5
I’ve checked all the gaskets including the TB and intake gaskets and I’ve checked the entire bay including brake boosters for vac leaks
 

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Discussion Starter #6
I’ll try cleaning the iacv because I didn’t clean it before installing it
 

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Discussion Starter #8
I can’t use the original one because it got stuck on and the bolts were stuck for ours me and my dad tryed and nothing so we just grabbed a grinder and mad slots in the screws and used a flathead and because of that the old iacv is really beat up and grinded I’ll take a look at the original one and see it anything internal is messed up fingers crossed
 

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I've only had to replace one IACV after attempting to clean the original one three times. I replaced it with an OEM one though so I have no experience with cheap aftermarket ones. With some other items Hondas seem to be really picky about using OEM though (like cam and crank position sensors, O2 sensors, etc).
 

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Discussion Starter #11
The one I bought seemed to be pretty good quality and every thing fit fine I don’t believe that’s would be the problem because either way it didn’t change anything it’s still idling the same as it was before and when I replaced it the iacv code went away
 

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Discussion Starter #12
But the reason I don’t think it’s that is it only surges when I start it for like 5-10 minutes but then it settles at 2k rpms
 

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Discussion Starter #13
But will the fact that it sat for about 5 years change anything like will it need a drive cycle or something?
 

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Shouldn't. Besides things getting dirty time shouldn't matter.

So once warmed up it idles at 2k rpm? Remove the intake then start the car, put two fingers over the IACV cutout. Does the engine keep running? This would point to a vacuum leak.
 

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Discussion Starter #15
Sry it took so long to reply but yes I have taken the intake off and plugged the whole the car sputters down quite a bit almost to a stall but does not and bc of that I have checked the car for a vacuum like twice I sprayed all the vacuum lines and gaskets including the tb and intake and nothing no change in idle I even checked the pcv valve bc I heard that can cause vacuum leak symptoms
 

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Discussion Starter #16
I have also had some people saying that the computer needs to re-learn itself but I have ran if for a few hours in total and nothing changed
 

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get a oem honda iac valve then perform a idle relearn procedure. make sure you clean where it mounts and seals to the throttle body. also clean the throttle plate.
 

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Discussion Starter #19
Should I try to clean my original iac to spin freely it looks to be in good shape also I have cleaned out the tb but how do I do an idle relearn procedure?
 

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its on the net and in here for instructions on the relearn, clean the old one or buy a new one its your choice but your wasting time deciding while it could have been done already. the relearn does not fix idle problems it teaches the pcm vacuum/map numbers above set idle during arm up.also check your throttle cable for being set to tight and binding.
 
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